Treatment characteristics and effects of nanoparticle zero-valent iron (nZVI) powder on nitrogen removal efficiency for sewage treatment

Abstract

This study aims at estimating nanoparticle typed zero-valent iron (nZVI) process as an advanced nitrogen removal technique. To focus on investigating characteristics and effects of nZVI on nitrogen removal for sewage treatment, batch reactor experiments were conducted to reduce excessive nitrate nitrogen (NO3-N). To improve NO3-N removal efficiency and to find a supporter or alternative of nZVI, silica sand, synthetic zeolite, and a mixture of silica sand, synthetic zeolite, and nZVI were used in the experiments. As a result of this study, the chemical denitrification by nZVI attracted on the magnet surface may be useful for total nitrogen removal in conventional sewage and wastewater treatment plants under the optimal conditions, and application of silica sand also is an excellent adsorbent or media for N-component removal and a supporter as well. This study concludes the end product in this study may be nitrogen gas (N2) through Fe reaction with O2 and NO3− in aerobic nZVI (Fe)–H2O system. Future study is required to examine the competition of nZVI between nitrate and many other compounds depending upon various experimental conditions for improving the nitrate removal efficiency and impeding the ammonium generation.